Concept: The question tests on the basics of Probablity
Solution:
Probability of selecting a red balloon = 1/6
Probability of not selecting a red balloon = 1 - 1/6 = 5/6
Probability of getting at least 1 red balloon = 1 - Probability of not getting a red balloon
If 3 balloons are selected, then the probability of not getting a red balloon = 5/6 * 5/6 * 5/6 = 125 / 216
Therefore probability of at least 1 red balloon = 1 - 125/216 = 91/216
Option A